The most important thing is to limit the amount of dust that you will create.
You have to determine the best texture for your carving.
Try carving at different 'water content textures' and see what feels best to you. Get a spray bottle just incase you may need to add a little water.

John 3:16
"For God so loved the world that He gave His only begotten Son, that whosoever believeth in Him should not perish but have everlasting life".

The answer lies with what you want your carving to look like as each stage will give you a different look. As your porcelain dries your lines will go from soft and flowing to sharp and precise. Also, every type of porcelain will react a bit differently at each stage with some being more forgiving than others.